As a member of several organizations, I'm constantly emailing updates on upcoming meetings and events. I use iCal religiously to keep track of everything, but it gets tedious having to retype all the details into an email.
Today I noticed that dragging an individual event off the iCal screen changes its appearance -- and sure enough, when I dropped the dragged event onto an email in Mail, it entered all the information perfectly. Hitting copy and paste works just as well, and any text field can use it.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20061217171135611